Starting at the same pressure and volume, which thermodynamical process results in the least work being done by the same gas? a. Isobaric expansion b. Isothermal expansion c. Adiabatic expansion

Adiabatic expansion (c)

Adiabatic expansion is defined as an ideal behaviour for a closed system, in which the pressure is constant and the temperature is decreasing.

An adiabatic expansion has less work done and no heat flow, thereby a lower internal energy comparing to an isothermal expansion which has both heat flow and work done and temperature decreases during adiabatic expansion.